/Engine/Source/Runtime/GeometryCore/Public/Operations/LocalPlanarSimplify.h
Test if the triangles connected to a vertex could be flattened by folding along the given edge
Whether all the triangles were coplanar
static bool IsDevelopableAlongEdge ( const [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) & Mesh, int EID, int VID, double DotTolerance, FVector3d & NormalA, bool & bIsFlat )